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Anthony Daniele

Please do NOT make changes to this Sandbox until after April 23, 2010. Sandboxes 151-200 are reserved until then for use by the Chemistry 307 class at UNBC taught by Prof. Andrea Gorrell.

Contents 1 Chloramphenicol Acetyltransferase Type III 1.1 Introduction 1.1.1 Reaction of CAT III 1.2 Structure

Chloramphenicol Acetyltransferase Type III

Chloramphenicol acetyltransferase type III (CAT III) is an enzyme which catalyzes the transfer of an acetyl group from acetyl-CoA to hydroxyl groups of chloramphenicol. CAT III is a trimeric protein

Introduction

Reaction of CAT III

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In the first step of the reaction, Histidine-156 abstracts a proton from the 3-hydroxyl of chloramphenicol, promoting a nucleophilic attack from the deprotonated oxygen to the thioester bond of the acetyl-CoA. The intermediate produced, 3-acetylchloramphenicol, then rearranges non-enzymatically to 1-acetylchloramphenicol. Regeneration of the 3-hydroxyl allows another CAT III catalyzed nucleophilic attack to another acetyl-CoA and a 1,3-diacetylchloramphenicol product is formed.

Structure

spinqualitylabelsall models PDB ID 4CLA Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image